The present invention generally relates to a method for forming optical fiber and, more particularly relates to a method of introducing perturbations into the optical fiber during the fiber draw process.
Conventional manufacturing processes for producing optical fibers typically include drawing an optical fiber from an optical fiber preform in a draw furnace, cooling the drawn fiber, and coating the fiber after it has substantially cooled. Significant efforts have been made to improve the bandwidth of multimode fibers to increase the yield of the fiber production. Some efforts have attempted to enforce the index profile accuracy. One approach to improve the bandwidth is to introduce mode coupling in multimode fibers. Some attempts have proposed spinning or twisting the fiber to improve the multimode bandwidth to cause short range refractive index variations or perturbations that cause mode mixing. However, fiber spinning can have complex effects on both the glass and the coating and may damage the coating which may introduce attenuation.
It is therefore desirable to provide for a method of producing an optical fiber to introduce perturbations into the fiber without the drawbacks of prior approaches.